Terminal means for ignition cables



July 19, 1966 F. s. SLICK 3,262,085

TERMINAL MEANS FOR IGNITION CABLES Filed Sept. 21. 1964 /& 49 Y 40 32 /d j E i1 T H 1 INVENTOR.

FRED .5. Juan.

United States Patent 3,262,085 TERMINAL MEANS FOR IGNITION CABLES Fred S. Slick, Rockford, Ill., assignor to Slick Electro Incorporated, Rockford, 111., a corporation of Illinois Filed Sept. 21, 1964, Ser. No. 397,691 2 Claims. (Cl. 339-100) This invention relates to terminal means for ignition cables, and especially to a means that assures a positive contact between the terminal means and the equipment with which the cable is assembled, such as a magneto or the like.

This invention employs, as an element thereof, the cable forming the subject matter of my application, Serial No. 331,519, for a Non-buckling Cable, and comp-rises a novel means of assembling a resilient contact means with the cable of the above application.

An object of this invention is to provide means that will assure a positive, uninterrupted flow of current through the ignition system.

Another object is to provide a terminal means that will not permit interruption of current during periods of vibration.

Another object is to provide a terminal means that will maintain a positive contact, and one not interrupted by corrosion.

Another object is to provide a terminal means that is urged into a positive contact by a resilient member.

Another object is to provide a terminal means that avoids the use of solder which may melt and interrupt the flow of the current.

Further objects and advantages of this invention will become apparent from a consideration of the following detailed description taken in connection with the accompaying drawing wherein an embodiment of the invention is shown. It is, however, to be understood that the invention is not limited to the details disclosed, but includes all such variations as fall within the spirit of the invention.

Referring to the drawing:

FIG. 1 is an enlarged fragmentary axial cross-section of the invention assembled with a magneto or similar instrument.

FIG. 2 is a fragmentary sectional view, considerably enlarged, of the terminal assembled with an ignition cable.

FIG. 3 is a section taken at 3-3 of FIG. 2.

FIG. 4 is an enlarged view of the preferred terminal pin.

FIG. 5 is an end view of the pin of FIG. 4.

FIG. 6 is an enlarged side view of the helical terminal member.

FIG. 7 is an end view of the terminal member shown in FIG. 6.

FIG. 8 is an enlarged view of a modified form of the terminal pin, and

FIG. 9 is .an end view of the terminal pin of FIG. 8.

Referring again to the drawing: In the present instance the invention is assembled with a magneto having a distributor housing 10 and a distributor head 12, assembled in the usual manner.

Distributor housing 10 has an internal threaded portion 14.

The cable assembly 16 comprises a cable 18 having an external, woven metalic grounding shield 20. A nut 22 is threadedly engaged in portion 14 and surrounds the shield 20. A tapered ferrule 24 freely surrounds the cable 18 after a portion of the shield 20 has been removed and flared as at 26. The flare 26 covers the ferrule 24 as shown in FIG. 1. A resilient sealing ring 28 is placed intermediate ferrule 24 and the edge 30 of a recess 32, provided in housing 10. A ring 34 having a bore complementary to the taper of ferrule 24 is positioned adjacent 3,262,085 Patented July 19, 1966 "ice to the end of nut 22 and over the flared portion of shield 20 as shown in FIG. 1. When nut 22 is threaded into portion 14, ring 34 is moved axially and the flared portion of shield 20 is held securely against axial displacement on the ferrule 24. Consequently, cable 18 is also prevented from being displaced axially. The removal of shielding 20 exposes the insulation-covering 36 which extends into a cavity 38 of distributor head 12 to an end indicated 39 as shown in FIGS. 1 and 2. A sleeve 40 of semi-rigid insulating material having a first bore 42 is placed over the covering 36 and terminates as at 44. Bore 42 terminates in a face at 39 to form an abutment or wall for limiting the axial, inward position of the cable-covering 36.

Cable 18 comprises a conductor 48 in the form of an open helix of the type described in my pending application Serial No. 331,519, now abandoned. Cable covering 36 completely surrounds the conductor 48 as shown in FIGS. 2 and 3.

Distributor head 12 is provided with a plurality of contact posts 46, only one being shown, and which are molded therein as shown in FIG. 1. Posts 46 are provided with a head such as 49, and which is exposed at the bottom of cavity 38.

The gist of this invention is embraced in a resilient helical terminal 50 as shown in FIGS. 1, 2, 6 and 7, and an anchor pin 53 shown in FIGS. 2 through 5, and which pin supports the terminal member 50 integrally with conductor 48. Terminal 50 comprises a helical member preferably of stainless steel wire and wound into a plurality of spaced coils 5-2. Terminal 50 terminates in a plurality of coils 54 of a reduced diameter, the several coils 54 being, in this instance, substantially in mutual contact, but not necessarily so.

Anchor pin 53 is of a suitable material such as stain less steel, or the like, and comprises a tapered shank 56 of a suitable length and having an undefaced peripheral surface and which shank is of a mean diameter approximately that of the inner diameter of the conductor 48, and terminates in a noint as at 58. A body portion 60 of a diameter greater than that of shank 56 is provided, in this instance, with a right-hand thread of #3-48 size.

Coils 54 of terminal 50 have been wound right-hand and in close contact so that when coils 54 are threadedly engaged with the thread of body 60, of pin 53, the coils will be separated axially and thus be in frictional engagement with the threads of the body portion. Thus there will be no danger of current interruption .at this point. After assembly of pin 53 and terminal 50, as above, the assembly of the complete unit 16 is then in order.

Shank 56 of pin 53 is next inserted into the bore of the conductor which is drilled to remove the insulating material as at 62. By a left-hand rotation of terminal 50 and urging the shank 53 axially into hole 62, the shank 53 will expand the bore of conductor 48 which has a lefthand spiral. Thus shank 53 will freely enter hole 62 and come to a stop when body 60 abuts the insulation of cable 18 as at 39 of FIG. 2. When turning of pin 53 has stopped, the coils of conductor 48 will grip the tapered shank 56, thus assuring a good contact.

Sleeve 40 is provided with an opening 64 slightly larger than the coils 54 after their assembly with body 60 of pin 53. The final assembly as shown in FIG. 1 is selfexplanatory and need not be furth'er described.

FIG. 8 shows .a modified form 66 of the anchor pin. Body portion 68 is similar to anchor pin body portion 60. The shank 70, however comprises three cylindrical axially-adjoining portions 72, 74 and 76, which are of diameters increasing toward the body portion 68, step 72 being the smallest. This design does not have the tendency to shift axially; the pressure on the pin being normal to the axis. It is believed that the tolerances allowed 3 when forming the coiled conductor will be such that one of the steps 72, 74 and 76 will be of a diameter to frictionally grasp the bore of the conductor 48.

While this invention has been described as being assembled with a magneto, it is to be understood that it can be employed in making similar connections with other components, such as spark plugs, coils, etc.

It is to be understood that when assembling the cable 16 with a magneto as shown in FIG. 1, care should be taken to assure a compression axially of terminal 50 between surface 44 and head 49; this will assure a positive contact.

The above being a complete description of an illustrative embodiment of the invention, What is claimed as new and desired to be secured by Letters Patent of the United States is:

1. A terminal means for a cable, said cable having a helical conductor surrounded by a sheath of insulating material, in combination a sleeve of semi-rigid insulating material having a first axial bore to receive said sheath, said bore terminating in an abutment, said sleeve terminating axially beyond said abutment in a face, and having a second axial bore of a diameter less than that of said first bor'e extending from said abutment to said face, a terminal anchor pin comprising a tapered shank of a References Cited by the Examiner UNITED STATES PATENTS 2,353,322 7/1944 Stoifel et al 339-268 X 2,719,278 9/1955 Kernen et a1 339-l00 2,809,359 10/1957 Slick 339l00 3,109,691 11/1963 Burkhardt 339100 FOREIGN PATENTS 1,229,047 2/1960 France.

EDWARD C. ALLEN, Primary Examiner. W. DONALD MILLER, Examiner. 

1. A TERMINAL MEANS FOR A CABLE, SAID CABLE HAVING A HELICAL CONDUCTOR SURROUNDED BY A SHEATH OF INSULATING MATERIAL, IN COMBINATION A SLEEVE OF SEMI-RIGID INSULATING MATERIAL HAVING A FIRST AXIAL BORE TO RECEIVE SAID SHEATH, SAID BORE TERMINATING IN AN ABUTMENT, SAID SLEEVE TERMINATING AXIALLY BEYOND SAID ABUTMENT IN A FACE, AND HAVING A SECOND AXIAL BORE OF A DIAMETER LESS THAN THAT OF SAID FIRST BORE EXTENDING FROM SAID ABUTMENT TO SAID FACE, A TERMINAL ANCHOR PIN COMPRISING A TAPERED SHANK OF A MEANS DIAMETER APPROXIMATING THAT OF THE INNER DIAMETER OF SAID HELICAL CONDUCTOR AND HAVING A BODY CO-AXIAL WITH, AND INTEGRAL WITH SAID SHANK, SAID BODY PORTION HAVING A EXTERNAL THREAD, AND A HELICAL TERMINAL HAVING A PLURALITY OF AXIALLY-SPACED MAJOR COILS AXIALLY ABUTTING SAID FACE AND TERMINATING IN A PLURALITY OF MINOR COILS, SAID MINOR COILS BEING THREADEDLY ENGAGED TO SAID BODY PORTION WITHIN SAID SECOND BORE. 